In metaphysics, substance is a term used to describe the fundamental essence of a thing. It refers to the underlying reality that makes an object what it is. The concept of substance has been debated by philosophers for centuries, and its meaning has evolved over time.

History of Substance in Metaphysics

The idea of substance can be traced back to Aristotle, who believed that everything in the universe is composed of two things: matter and form. Matter refers to the physical material that something is made of, while form refers to the shape or structure that gives it its identity. According to Aristotle, substance is the combination of matter and form.

Later philosophers such as René Descartes and Immanuel Kant built on this idea, proposing their own definitions of substance. Descartes believed that substance was an independent entity that existed separately from the physical world. Kant argued that substance was a necessary concept for understanding causality.

Substance vs. Accidents

In addition to defining what substance is, philosophers have also distinguished it from accidents. Accidents are properties or qualities that are not essential to an object’s identity but can vary without changing its fundamental nature. For example, the color of a car or the weight of a book are accidents because they can change without altering the object’s underlying substance.

Examples of Substance

So what are some examples of substances? In Aristotelian philosophy, substances were often identified with natural kinds or species such as animals or plants. Each species had its own unique form or essence that made it different from other species.

In modern philosophy, substances may be identified with individual objects such as people or tables, as well as abstract entities like numbers or concepts.

The Role of Substance in Metaphysics

The concept of substance plays an important role in metaphysics because it helps us understand what makes things the way they are. By identifying the underlying substance of an object, we can gain insight into its essential nature and properties.

Substance also helps us distinguish between what is essential and what is accidental about an object. This can be useful in fields such as science, where scientists seek to understand the underlying laws and principles that govern the natural world.


In conclusion, substance is a complex and multifaceted concept that has been debated by philosophers for centuries. While its meaning may have evolved over time, it remains a crucial concept in metaphysics for understanding the fundamental nature of things. By distinguishing between substance and accidents, we can gain a deeper understanding of the world around us and the objects within it.